PRACTICAL MECHANICS FOR BOYS TEXT

|in Degrees Fahrenheit +---------+------------ Mixtures | From | To -----------------------------------------------+---------+------------ Common salt, 1 part; snow, 3 parts | 32 | zero .0 Common salt, 1 part; snow 1 part | 32 | -.4 Calcium chloride, 3 parts; snow 1 part | 32 | -27 Calcium chloride, 2 parts; snow 1 part | 32 | -44 Sal ammoniac, 5 parts; salt-peter 5 parts; | | water 16 parts. | 50 | -10 Sal ammoniac, 1 part; salt-peter 1 part; | | water 1 part | 46 | -11 Ammonium nitrate, 1 part; water 1 part | 50 | -3 Potassium hydrate, 4 parts; snow 3 parts | 32 | -35 -----------------------------------------------+---------+------------ IGNITION TEMPERATURES. Phosphorus 120 degrees Fahrenheit Bi-sulphide of carbon 300 " " Gun-cotton 430 " " Nitro-glycerine 490 " " Phosphorus, amorphous 500 " " Rifle powder 550 " " Charcoal 660 " " Dry pine wood 800 " " Oak 900 " " POWER AND HEAT EQUIVALENTS. In studying matters pertaining to power and heat, certain terms are used, such as horsepower, horsepower-hours, watts, watt-hours, kilowatt, kilowatt-hours, foot-pounds, joule, and B. T. U. (British Thermal Unit). The following tables give a comprehensive idea of the values of the different terms: 1 Horsepower-hour = 0.746 kilowatt-hour = 1,980,000 foot-pounds of water evaporated at 212 degrees Fahrenheit, raised from 62 degrees to 212 degrees. 1 Kilowatt-hour = 1,000 watt-hours = 1.34 horse-power-hours = 2,653,200 foot-pounds = 3,600,000 joules = 3,420 B. T. U. = 3.54 pounds of water evaporated at 212 degrees = 22.8 pounds of water raised from 62 to 212 degrees. 1 Horsepower = 746 watts = 0.746 kilowatts.= 33,000 foot-pounds per second = 2,550 B. T. U. per min. = 0.71 B. T. U. per second = 2.64 pounds of water evaporated per hour at 212 degrees. 1 Kilowatt = 1,000 watts = 1.34 horsepower = 2,653,200 foot-pounds per hour = 44,220 foot-pounds per min. = 737 foot-pounds per second = 3,420 B. T. U. per hour = 57 B. T. U. per min. = 0.95 B. T. U. per second = 3.54 pounds of water evaporated per hour at 212. 1 Watt = 1 joule per second = 0.00134 horse-power = 0.001 kilowatt = 342 B. T. U. per hour = 44.22 foot-pounds per min. = 0.74 foot-pounds per second = 0.0035 pounds of water evaporated per hour at 212 degrees. 1 B. T. U. (British Thermal Unit) = 1,052 watt-seconds = 778 foot-pounds = 0.252 calorie = 0.000292 kilowatt-hours = 0.000391 horsepower-hour = 0.00104 pounds of water evaporated at 212 degrees. 1 Foot-pound = 1.36 joule = 0.000000377 kilowatt-hour = 0.00129 B. T. U. = 0.0000005 horsepower-hour. 1 Joule = 1 watt-second = 0.000000278 kilowatt-hour = 0.00095 B. T. U. = 0.74 foot-pounds. CHAPTER XVII INVENTIONS AND PATENTS, AND INFORMATION ABOUT THE RIGHTS AND DUTIES OF INVENTORS AND WORKMEN There is no trade or occupation which calls forth the inventive faculty to a greater degree than the machinist's. Whether it be in the direction of making some new tool, needed in some special work, or in devising a particular movement, or mechanical expedient, the machinist must be prepared to meet the issues and decide on the best structural arrangement. Opportunities also come daily to the workers in machine shops to a greater extent than other artisans, because inventors in every line bring inventions to them to be built and experimentally tested. A knowledge of the rights and duties of inventors, and of the men who build the models, is very desirable; and for your convenience we append the following information: The inventor of a device is he who has conceived an idea and has put it into some concrete form. A mere idea is not an invention. The article so conceived and constructed, must be both _new_ and _useful_. There must be some utility. It may be simply a toy, or something to amuse. If A has an idea, and he employs and pays B to work out the device, and put it into practical shape, A is the inventor, although B may have materially modified, or even wholly changed it. B is simply the agent or tool to bring it to perfection, and his pay for doing the work is his compensation. An inventor has two years' time within which he may apply for a patent, after he has completed his device and begun the sale of it. If he sells the article for more than two years before applying for a patent, this will bar a grant. Two or more inventors may apply for a patent, provided each has contributed something toward bringing it to its perfected state. Each cannot apply separately. The patent issued will be owned by them jointly. Joint owners of a patent are not partners, unless they have signed partnership papers respecting the patent. Because they are partners in some other enterprise, disconnected from the patent, that does not constitute them partners in the patent. They are merely joint owners. If they have no special agreement with respect to the patent each can grant licenses to manufacture, independently of the others, without being compelled to account to the others, and each has a right to sell his interest without asking permission of the others. An _inventor_ is one who has devised an invention. A _patentee_ is one who owns a patent, or an interest in one, be he the inventor or not. The United States government does not grant Caveats. The only protection offered is by way of patent. A patent runs for a period of seventeen years, and may be renewed by act of Congress only, for a further term of seven years. An interference is a proceeding in the Patent Office to determine who is the first inventor of a device. The following is a brief statement of the course followed: When two or more applicants have applications pending, which, in the opinion of the Examiner, appear to be similar, the Office may declare an interference. If an applicant has an application pending, and the Examiner rejects it on reference to a patent already issued, the applicant may demand an interference, and the Office will then grant a hearing to determine which of the two is entitled to the patent. The first step, after the declaration of interference, is to request that each applicant file a preliminary statement, under oath, in which he must set forth the following: First: The date of conception of the invention. Second: Date of the first reduction to writing, or the preparation of drawings. Third: Date of making of the first model or device. Fourth: When a complete machine was first produced. These statements are filed in the Patent Office, and opened on the same day, and times are then set for the respective parties to take testimony. If one of the parties was the first to conceive and reduce to practice, as well as the first to file his application, he will be adjudged to be the first inventor, without necessitating the taking of testimony. If, on the other hand, one was the first to conceive, and the other the first to file, then testimony will be required to determine the question of invention. The granting of a patent is not conclusive that the patentee was, in reality, the first inventor. The law is that the patent must issue to the _first_ inventor, and if it can be proven that another party was the first, a new patent will issue to the one who thus establishes his right. The Commissioner of Patents has no right to take away the patent first issued. Only the Courts are competent to do this. A patent is granted for the right to _make_, to _use_ and to _vend_. An owner of a patent cannot sell the right only to make, or to sell, or to use. Such a document would be a simple license, only, for that particular purpose. A patent may be sold giving a divided, or an undivided right. A divided right is where a State, or any other particular territorial right is granted. An undivided right is a quarter, or a half, or some other portion in the patent itself. If an inventor assigns his invention, and states in the granting clause that he conveys "all his right and title in and to the invention," or words to that effect, he conveys all his rights throughout the world. If the conveyance says, "all rights and title in and throughout the United States," he thereby reserves all other countries. If a patent is issued, and the number and date of the patent are given, the assignment conveys the patent for the United States only, unless foreign countries are specifically mentioned. To convey an invention or patent, some definite number or filing date must be given in the document, with sufficient clearness and certainty to show the intent of the assignor. An invention does not depend on quantity, but on quality. It is that which produces a new and a useful _result_. In the United States patents are granted for the purpose of promoting the useful arts and sciences. In England, and in many other foreign countries, patents are granted, not on account of any merit on the part of the inventor, but as a favor of the crown, or sovereign. Originally patents were granted by the crown for the exclusive privilege in dealing in any commodity, and for this right a royal fee was exacted. >From this fact the term _royalty_ originated. An international agreement is now in force among nearly all countries, which respects the filing of an application in any country, for a period of one year in the other countries. In making an application for a patent, a petition is required, a specification showing its object, use, and particular construction, followed by a claim, or claims, and accompanied by a drawing, if the invention will permit of it, (which must be made in black, with India ink), and an oath. The oath requires the following assertions: That the applicant is the first and original inventor of the device, and that he does not know and does not believe the same was ever known or used before his invention or more than two years before his application. He must also further allege that the invention was not patented or described in any printed publication here or abroad, and not manufactured more than two years prior to the application, and that he has not made an application, nor authorized any one to do so more than two years prior to his application. The first Government fee is $15, payable at the time of filing, and the second and final fee is $20, payable at the time the patent is ordered to issue. The filing of an application for patent is a secret act, and the Patent Office will not give any information to others concerning it, prior to the issue of the patent. GLOSSARY OF WORDS USED IN TEXT OF THIS VOLUME Abrupt. Suddenly; coming without warning. Abrasive. A material which wears away. Actuate. Influenced, as by sudden motive; incited to action. Accumulate. To bring together; to amass; to collect. Acoustics. The branch of physics which treats of sound. Adhesion. To hold together; a molecular force by means of which particles stick together. Affinity. Any natural drawing together; the property or force in chemicals to move toward each other. Aggravate. To incite; to make worse or more burdensome. Alloy. A combination of two or more metals. Altitude. Height; a vertical distance above any point. Alkali. Any substance which will neutralize an acid, as lime, magnesia, and the like. Amalgam. Any compound of metal which has mercury as one of the elements. Amiss. Wrong, fault, misdeed. Annealing. A process of gradually heating and cooling metals, whereby hardness and toughness are brought about. Angle plate. A metal structure which has two bodies, or limbs, at right angles to each other. Analysis. The separating of substances into their elementary forms. Anchor bolt. A structure intended to be placed in a hole in a wall, and held there by a brew which expands a part of the structure. Apprentice. One who is learning a trade or occupation. Artificial. That which resembles the original; made in imitation of. Arbor. A shaft, spindle, mandrel, or axle. Armature. A metallic body within the magnetic field of a magnet. Arbitrary. Stubborn determination. Doing a thing without regard to consequences. Artisan. One skilled in any mechanical art. Attributable. That which belongs to or is associated with. Automatically. Operating by its own structure, or without outside aid. Augmented. Added to; to increase. Auxiliary. To aid; giving or furnishing aid. Avoirdupois. The system of weights, of which the unit is sixteen ounces. Back-saw. A saw which has a rib at its upper margin. Barleycorn. A grain of barley. Bastard. A coarse-grained file. B. T. U. British Thermal Unit. Back-gear. That gear on a lathe for changing the feed. Bevel. Not in a right line; slanting; oblique. Bibb. A form of water faucet. Bit, or bitt. A form of tool for cutting purposes on a lathe, planer, shaper, or drilling machine. Borax. A white crystalline compound, of a sweetish taste. Chemically it is sodium biborate. Buffs. Usually a wheel covered with leather or cloth, and having emery dust on it, for fine polishing purposes. Buffeted. Thrown back. Bronze. An alloy of copper and tin. Calcium. Lime. Cant. A form of lever. Carbonate. A salt of carbonic acid. Caustic. Capable of corroding or eating away. Capillary. That quality of a liquid which causes it to move upwardly or along a solid with which it is in contact. Caliper. An instrument for spanning inside and outside dimensions. Centripetal. The force which tends to draw inwardly, or to the center. Centrifugal. The outwardly-moving force from a body. Centering. To form a point equidistant from a circular line. Chloride. A compound of chlorine with one or more positive elements, such as, for instance, salt. Circular pitch. The measurement around a gear taken at a point midway between the base and end of the teeth. Circumference. The outside of a circular body. Clef. A character placed on a staff of music to determine the pitch. Clutch. A mechanical element for attaching one part to another. Chuck, Independent. A disk of metal to be attached to the live spindle of a lathe, and which has on its face a set of dogs which move radially independently of each other. Chuck, Universal. A disk to be attached as above, provided with dogs which are connected so they move radially in unison with each other. Classified. Arranged in order, in such a manner that each of a kind is placed under a suitable heading. Clearance. To provide a space behind the cutting edge of a tool which will not touch the work being cut. Consistency. Harmonious; not contradictory. Coherer. That instrument in a wireless telegraphy apparatus which detects the electrical impulses. Commutator. The cylindrical structure on the end of an armature, which is designed to change the polarity of the current. Concentrated. Brought together at one point. Coinage. The system of making money from metals. Compound. The unity of two or more elements. Constant. Being insistent and consistent; also a term to be used in a problem which never varies. Conversion. The change from one state to another. Cone. A body larger at one end than at another; usually applied to a form which is cylindrical in shape but tapering, from end to end. Compression. The bringing together of particles, or molecules. Convolute. A spiral form of winding, like a watch spring. Coiled. A form of winding, like a string wound around a bobbin. Conductivity. Applied generally to the quality of material which will carry a current of electricity; also a quality of a material to convey heat. Cohesion. The force by which the molecules of the same kind are held together. Concentric. A line which is equidistant at all points from a center. Confined. Held within certain bounds. Corpuscular. Molecular or atomic form. Converge. To come together from all points. Concave. A surface which is depressed or sunken. Convex. A surface which is raised, or projects beyond the surface of the edges. Component. One of the elements in a problem or in a compound. Coefficient. A number indicating the degree or quality possessed by a substance. An invariable unit. Cube. A body having six equal sides. Cross-section. A term used to designate that line which is at right angles to the line running from the view point. Cross slide. The metal plate on a lathe which holds the tool post, and which is controlled, usually, by a screw. Contiguous. Close to; near at hand. Countersink. The depression around a bore. Collet. A collar, clutch or clamping piece, which has jaws to hold a bar or rod. Countershaft. A shaft which has thereon pulleys or gears to connect operatively with the gears or pulleys on a machine, and change the speed. Conducive. Tending to; promotive of a result. Corundum. An extremely hard aluminum oxide used for polishing. Cold chisel. A term applied to an extremely hard chisel used for cutting and chipping metal. Combustion. The action or operation of burning. Conjunctively. Acting together. Comparatively. Similitude or resemblance, one with another. Cotter. A key to prevent a wheel turning on its shaft. Dead center. A term used to designate the inoperative point of the crank. Depicting. Showing; setting forth. Deodorant. A substance which will decompose odors. Developer. A chemical which will bring out the picture in making the film or plate in photography. Decimeter. The length of one-tenth of a meter in the metric system. Decameter. The length of ten meters in the metric system.